If you have a psp charger use that one to test it ,just make sure it is a real official psp charger tho ,yep try what WizardStan said ,try out the usb.
Also ,take the battery out and just run it through the charger and if it powers on ok ,move the charger cable about a little to see if there are any breaks in the line.
If your charger is working try this ... kill your battery ,run it dry first and then remove it and power on the pandora with just the charger ,boot it up and turn it on to standby ,then when the screen os off ,remove the charger cable.Then put your drained battery back in to the pandora ,make sure it's nice and tight fitted with the lid on and plug your charger back in ,boot up and then go back into standby ,do something for one hour and then come back and do this ......
take the pandora out of standby then hold the pandora key down ,turn the power switch on the pandora to the right direction as if you are turning it on/off ,the pandora will reboot and reset the battery info and boot up ,then check your battery level ,if it's at zero then you have a failing battery,if the charge is under 10% you have a failing battery if it's over 15% you have a battery that needs to be charged properly and you should then let it charge for upto 4 hours.